Posts Tagged ‘osteoarthritis’

Like other senior fitness professionals, Janie Clark, president of the American Senior Fitness Association (SFA), has served many clients with osteoarthritis. In addition, Janie’s all-time favorite mare, the late great “Squall Moon,” suffered from the condition during her senior years. So here at SFA we are especially pleased to share the following University of Florida Health Science Center news release describing new progress in the fight against osteoarthritis:

University of Florida researchers are developing a gene therapy technique that could help both humans and horses fight osteoarthritis, a debilitating condition that causes inflammation and deterioration of the joints. The goal is to create a one-time treatment that works long term.

The research team received a highly competitive one-year, $900,000 grant from the National Institute of Health’s National Institute of Arthritis, Musculoskeletal and Skin Disease to fund the work. The new effort will expand laboratory studies into trials that better approximate osteoarthritis in humans.

The work will involve the use of viruses, called adeno-associated viruses, or AAV, as vehicles to deliver genetic material to the joints of horses, where it would produce a therapeutic protein directly at the site of the disease.

“We’re uniquely poised to do this study, because UF has a leading program in equine medicine and research and is one of the homes of AAV technology,” said principal investigator Steven Ghivizzani, Ph.D., a professor of orthopaedics and rehabilitation in the UF College of Medicine, and a member of the UF Genetics Institute. Researchers at UF’s Powell Gene Therapy Center are among the pioneers of AAV technology and gene therapy applications for a number of diseases./p>

Osteoarthritis, the most common type of arthritis, is a chronic condition that affects large weight-bearing joints such as the knees and hips. In osteoarthritis, the cartilage in the joints that usually allows bones to move smoothly over each other wears away, causing bones to rub. The result is pain, stiffness and swelling. About 27 million Americans age 25 and older have the disease, according to the National Institutes of Health. The economic cost of arthritis and other rheumatic conditions is estimated at close to $130 billion a year, according to the Centers for Disease Control and Prevention.

There is no cure for osteoarthritis.

Joint replacement surgery can help ease the disabling effects of the condition. The few medicines that exist for osteoarthritis mostly offer only limited symptom relief. In addition, those drugs can have unwanted consequences. Corticosteroid injections, for example, which are given to both people and horses, also suppress other healthy activities in the joint, such as processes important for healing. The injections also have to be administered repeatedly, which increases the chance of infection.

In contrast, the new gene therapies being developed at UF would require a one-time treatment and would not hinder the body’s healing processes.

Research suggests that the pain, joint inflammation and loss of cartilage associated with osteoarthritis are linked to a protein called interleukin-1. A therapeutic gene used to treat the arthritic joints produces a second protein that naturally counteracts the effects of interleukin-1, but that has not yet translated into effective treatments for patients because of difficulty getting high enough concentrations inside affected joints.

The UF researchers are devising a gene therapy approach that would allow continued production of therapeutic protein within the joints, directly at the disease site. Unlike existing drugs, the potential one-time treatment would not just address symptoms, but change the course of the disease.

“Dr. Ghivizzani is at the forefront of trying to develop new technologies for treating osteoarthritis and other joint diseases by gene therapy,” said Christopher Evans, D.Sc., Ph.D., theMaurice Müller professor of orthopaedic surgery at Harvard Medical School, who is not involved in the UF study. “There’s a lot riding on this.”

Previous studies in small animals such as rats demonstrated that delivery of the gene therapy resulted in meaningful levels of gene expression within affected joints. The researchers will examine how that translates to the larger joints of horses, which are more similar to human joints in terms of size, tissue structure and weight-bearing stance.

The new studies will determine the therapy dose that can be given safely, how much of the therapeutic protein is produced in the joint — and for how long — and the effectiveness of the therapy.

The researchers will use techniques such as a minimally invasive procedure called arthroscopy, imaging studies such as MRI and X-ray, as well as hands-on clinical evaluations to check for inflammation and cartilage degradation. Motion capture analysis will help with evaluation of changes in gait, a good measure of pain.

“We hope that this will be at least the first step in a therapy that will benefit both people and animals,” said Patrick Colahan, D.V.M., a board-certified equine surgeon in the UF College of Veterinary Medicine and co-investigator on the study. “It has the potential to help lots of different species, and from a veterinarian’s perspective, that’s what we’d like.”

It may make common sense that the pain relief gained through knee replacement surgery would instigate more physical exercise and, thereby, better weight control. But that is not what researchers found when they tracked 106 patients for two years following their knee replacements. Instead, 66 percent of the subjects had gained an average of 14 pounds.

The good news is that the other one-third had lost, on average, approximately four pounds. In those who lost weight, no decline in quadriceps strength was seen, whereas the quadriceps had weakened in those who gained weight.

Researchers explained that, after surgery, single knee replacement patients have a tendency to place more weight on the knee that wasn’t replaced. The added load of weight gain can compromise both knees and, in particular, may hasten the progression of osteoarthritis in the non-operated joint.

In summary, knee replacement patients should take care to maintain a healthy body weight. If knee pain persists following the surgery, such patients may wish to consider swimming, pool aerobics or other joint-sparing workouts designed to control weight and promote heart health.

For elderly patients a knee replacement may do more than reduce the pain associated with osteoarthritis of the knee, according to a study described at the annual meeting of the American Academy of Orthopaedic Surgeons in March. A new knee joint may also improve balance.

The study's subjects were 63 persons, average age 73, who underwent total knee replacements. One year following their surgeries, all of the subjects enjoyed significant improvement regarding measures of balance. "We are learning that pain relief may not be the only benefit that improves function after knee replacement," said the study's lead author Dr. Leonid Kandel, as reported by HealthDay.

Interestingly, researchers found that the relationship between improved balance and the patients' ability to walk and perform ADLs (activities of daily living) was stronger than that between decreased pain and their ability to walk and perform ADLs.

Conventional wisdom long held that low impact training helps spare the joints of mid-life and older adult exercisers. In recent times, however, impact forces have been advised for good bone health in some sectors of the literature. On the pro-impact side, there are inconsistencies among the recommendations of influential guideline-setting agencies, ranging from: (1) moderate to high intensity, incorporating jumping; to (2) medium impact, such as intermittent jogging or step aerobics; to (3) high impact for osteoporosis prevention, but low impact for its management.

Now comes a study that brings the question full circle. Recently presented at the annual meeting of the Radiological Society of North America, the investigation involved 100 male and 136 female subjects, ages 45 to 55, of normal weight and without symptoms of osteoarthritis. Researchers examined MRI scans of their knees and evaluated the results in relation to their physical activity patterns. The scientists concluded that high impact weight-bearing activities, like running and jumping, are risky for the health of knee cartilage in aging persons, whereas low impact activities, like cycling and swimming, may protect healthy knee cartilage from becoming diseased.

Is there a conflict between osteoporosis prevention and osteoarthritis prevention? While the jury is still out on the ideal level and frequency of impact in mature adult exercise training, prudence calls for caution, moderation and highly individualized programming, including activity-specific medical clearance to participate. Look for much more research and clarification to emerge in this important topic area in the future.

Muscle activation refers to the level of involvement of the muscle fibers in a skeletal muscle when it is working. Full activation occurs when all of the available fibers are used during a maximum-effort contraction. Many persons with knee osteoarthritis (OA) cannot fully activate their quadriceps (front thigh) muscles, which often are very weak.

A recent study published in the journal Arthritis & Rheumatism addressed the problem. Researchers at the University of Pittsburgh studied 111 subjects (minimum age: 40) with knee OA. Quadriceps strength and quadriceps activation (QA) were measured at baseline and after six weeks of training. The subjects were assigned to one of two specific training programs, both of which included quadriceps strengthening exercises.

After six weeks, strength gains were indeed found among the subjects, but one particular hypothesis of the scientists was not confirmed. They had expected baseline QA to be a strong predictor of which participants would respond best to either exercise plan. Instead, there was a broad range of divergence in strength gains, leading the researchers to conclude that variables other than QA score may be more useful in predicting which patients with knee OA are likely to benefit the most from quadriceps strengthening exercises.